This invention relates to electrochemical storage battery systems for deep ocean applications, and more particularly to systems for automatically activating electrochemical storage batteries when dropped into an ocean with devices for use at some depth, and for preventing the batteries from crushing due to the high external pressure at great ocean depths.
Some electronic devices intended to be dropped or released for operation at great depths in the ocean, such as ocean rescue devices, undersea markers, emergency equipment and sonobuoys, must be stored at some naval dock, air facility or oil drilling platform for extended periods before use. The storage is normally at ambient temperatures and pressures. If the device is delivered by aircraft to the site where it is to be put into use, as will usually be the case for emergency equipment, the device may be subjected to very low (-40.degree. C) temperatures during a high altitude flight. The device is then dropped into the ocean where it eventually comes to rest in an environment of low (0.degree. C) temperature and high (several thousand psi) pressure.
Such electronic devices are intended to operate on self contained power supplied by electrochemical storage batteries. Due to the high pressures encountered at deep ocean levels, it is necessary to take some steps to prevent the batteries from crushing. That is usually done with a surrounding pressure vessel, or by using specially designed seawater batteries. In either case, the cost of the device is significantly increased by the steps taken to prevent the batteries from crushing. It would be desirable to use commercially available batteries with only inexpensive modifications for extended shelf life and for instant operation at pressures up to 10,000 psi.